The remote control of endoscopic devices connected to each other through hard-wired connections is well known for performing surgical procedures. A plurality of devices including cameras, cutting tools, irrigation devices, light sources, and suction devices are connected via a network to a system controller. The system controller is capable of communicating with and controlling the various devices.
An endoscopic system with an irradiated light switching feature is disclosed in U.S. Pat. No. 7,258,663, issued Aug. 21, 2007. An endoscope of the system includes an image sensor incorporated in an insertion unit. The sensitivity of the image sensor can be varied by applying a plurality of pulsating driving signals thereto from a camera controller. The camera controller adjusts the sensitivity of the image sensor according to the type of endoscope employed. A separate light source provides light to a surgical site via a light guide extending through the insertion unit. The light is reflected at the surgical site and received by the image sensor. The insertion unit includes a memory that provides information as to the type of endoscope to the camera controller for the image sensor via a hard-wired connection. Further, a wired connection from a light source controller to the camera controller provides other parameters of the light source.
The '663 patent also discloses utilizing a light level sensor to calculate light output from an average of voltage levels of each video image output signal from the image sensor during one field or interval. This average value can be used to adjust the length of time of light source operation via a hard-wired connection by controlling the amount of time that the light source operates to minimize the amount of heat output from the light source. Light output adjustment is made with a diaphragm control command provided so that an iris diaphragm of the light source is opened or closed in response to the brightness detected by the image sensor. Thus, the intensity of light provided from the light source is automatically adjusted in view of the intensity of light sensed by the image sensor. The feedback arrangement of the '663 patent is provided by the hard-wired connection between the camera controller and the light source controller. The image sensor and light source provide light and sense light via the same insertion unit of an endoscope. Thus, the light source and camera controllers are located adjacent each other, and a hard-wired connection between the controllers is practical.
In some arthroscopic surgical procedures, however, the light source and the camera are provided with separate endoscopic devices. In such instances, providing a hard-wired connection between a camera controller and a light source controller is not practical as movement of the light source relative to the camera would be limited and awkward due to the presence of a connecting cable therebetween. Further, in some procedures, such as ENT procedures, a portable light-weight and compact hand-held light source unit is highly desirable. Further, a wired connection to a camera unit is not practical. Constant output of light by the hand-held light source requires a large battery that results in a heavier light source unit to be manipulated and an undesirable output of heat and thus presents a technical problem.
To reduce the amount of light output and thus energy needed by the portable light source unit, a goal is to synchronize periodic or intermittent operation of the light source with the image shutter of the video camera unit while maintaining sufficient light to obtain video images. The reduction in energy output from the light source increases the battery life of the existing battery. On the other hand, this reduction in light source usage enables the use of a smaller battery and thus a smaller and less heavy portable light source unit that also outputs less heat in operation. The inability to synchronize the video camera unit and the light source unit without a wired connection is a technical problem to be solved by the invention.